See also:

Heated Mirrors
For vehicles with heated mirrors: The heated outside rearview mirrors turn on when the rear window defogger is on and help to clear fog or frost from the surface of the mirrors. (Rear Window Defo ...

Underbody Maintenance
Use plain water to flush dirt and debris from the vehicle's underbody. Your dealer or an underbody car washing system can do this. If not removed, rust and corrosion can develop. ...

Customer Assistance for Text Telephone (TTY) Users (U.S. and Canada)
To assist customers who are deaf, hard of hearing, or speech impaired and who use Text Telephones (TTYs), GMC has TTY equipment available at its Customer Assistance Center. Any TTY user can communicat ...